Distributed process control systems, like those used in chemical, petroleum, industrial or other process plants, typically include one or more process controllers communicatively coupled to one or more field devices via analog, digital or combined analog/digital buses, or via a wireless communication link or network. The field devices, which may be, for example, valves, valve positioners, switches and transmitters (e.g., temperature, pressure, level and flow rate sensors), are located within the process environment and generally perform physical or process control functions such as opening or closing valves, measuring process parameters, etc. to control one or more process executing within the process plant or system. Smart field devices, such as the field devices conforming to the well-known Fieldbus protocol may also perform control calculations, alarming functions, and other control functions commonly implemented within the controller. The process controllers, which are also typically located within the plant environment, receive signals indicative of process measurements made by the field devices and/or other information pertaining to the field devices and execute a controller application that runs, for example, different control modules which make process control decisions, generate control signals based on the received information and coordinate with the control modules or blocks being performed in the field devices, such as HART®, WirelessHART®, and FOUNDATION® Fieldbus field devices. The control modules in the controller send the control signals over the communication lines or links to the field devices to thereby control the operation of at least a portion of the process plant or system. For example, the controllers and the field devices control at least a portion of a process being controlled by the process plant or system.
Information from the field devices and the controller is usually made available over a data highway or communication network to one or more other hardware devices, such as operator workstations, personal computers or computing devices, data historians, report generators, centralized databases, or other centralized administrative computing devices that are typically placed in control rooms or other locations away from the harsher plant environment. Each of these hardware devices typically is centralized across the process plant or across a portion of the process plant. These hardware devices run applications that may, for example, enable an operator to perform functions with respect to controlling a process and/or operating the process plant, such as changing settings of the process control routine, modifying the operation of the control modules within the controllers or the field devices, viewing the current state of the process, viewing alarms generated by field devices and controllers, simulating the operation of the process for the purpose of training personnel or testing the process control software, keeping and updating a configuration database, etc. The data highway utilized by the hardware devices, controllers and field devices may include a wired communication path, a wireless communication path, or a combination of wired and wireless communication paths. The protocol or protocols used by the data highway may include any one or more process control network communication protocols, such as HART, WirelessHART, Fieldbus, Profibus, HART, 4-20 mA loops, and the like, and/or may include one or more general-purpose communication protocols, such as Ethernet or Wi-Fi.
As an example, the DeltaV™ control system, sold by Emerson Process Management, includes multiple applications stored within and executed by different devices located at diverse places within a process plant. A configuration application, which resides in one or more workstations or computing devices, enables users to create or change process control modules and download these process control modules via a data highway to dedicated distributed controllers. Typically, these control modules are made up of communicatively interconnected function blocks, which are objects in an object oriented programming protocol that perform functions within the control scheme based on inputs thereto and that provide outputs to other function blocks within the control scheme. The configuration application may also allow a configuration designer to create or change operator interfaces which are used by a viewing application to display data to an operator and to enable the operator to change settings, such as set points, within the process control routines. Each dedicated controller and, in some cases, one or more field devices, stores and executes a respective controller application that runs the control modules assigned and downloaded thereto to implement actual process control functionality. The viewing applications, which may be executed on one or more operator workstations (or on one or more remote computing devices in communicative connection with the operator workstations and the data highway), receive data from the controller application via the data highway and display this data to process control system designers, operators, or users using the user interfaces, and may provide any of a number of different views, such as an operator's view, an engineer's view, a technician's view, etc. A data historian application is typically stored in and executed by a data historian device that collects and stores some or all of the data provided across the data highway while a configuration database application may run in a still further computer attached to the data highway to store the current process control routine configuration and data associated therewith. Alternatively, the configuration database may be located in the same workstation as the configuration application.
In a process plant or process control system, when evidence of an abnormal condition or fault occurs (e.g., when an alarm is generated, or when a process measurement or actuator is found to have excessive variation), an operator, instrument technician or process engineer typically uses an analytics tool in combination with his or her knowledge of the process being controlled by the system and its flow path through the system to attempt to determine upstream measurements and process variables that may have contributed to the production of the evidence of the abnormal condition or fault. For example, an operator may use the DeltaV™ batch analytics product or another continuous data analytics tool to attempt to determine the contributions of various process variables and/or measurements to an abnormal or fault condition. Typically, an operator or user identifies candidate upstream factors (e.g., measurements, process variables, etc.) based on his or her knowledge of the process and provides these candidates to the analytics tool. Subsequently, these data analytics tools utilize principal component analysis (PCA) to determine which of the candidate upstream factors impact downstream predicted quality parameters. The process control systems that are currently commercially available typically do not provide information on the flow path through the process and associated measurements and actuators along this path, and instead rely on a human to input this information into analytics tools. Consequently, as the set of candidates that is input into the tool is filtered by a person, the list of candidates may be incomplete and/or erroneous, and may not be consistent from person to person.
Additionally, the architecture of currently known process control plants and process control systems is strongly influenced by limited controller and device memory, communications bandwidth and controller and device processor capability. For example, in currently known process control system architectures, the use of dynamic and static non-volatile memory in the controller is usually minimized or, at the least, managed carefully. As a result, during system configuration (e.g., a priori), a user typically must choose which data in the controller is to be archived or saved, the frequency at which it will be saved, and whether or not compression is used, and the controller is accordingly configured with this limited set of data rules. Consequently, data which could be useful in troubleshooting and process analysis is often not archived, and if it is collected, the useful information may have been lost due to data compression.
The limitations of currently known process plants and process control systems discussed above and other limitations may undesirably manifest themselves in the operation and optimization of process plants or process control systems, for instance, during plant operations, trouble shooting, and/or predictive modeling. For example, such limitations force cumbersome and lengthy work flows that must be performed in order to obtain data for troubleshooting and generating updated models, and even then, the troubleshooting results and models may be incomplete or not fully representative of the actual system, as the inputs to their generation rely on a particular operator's experience and knowledge.
“Big data” generally refers to a collection of one or more data sets that are so large or complex that traditional database management tools and/or data processing applications (e.g., relational databases and desktop statistic packages) are not able to manage the data sets within a tolerable amount of time. Typically, applications that use big data are transactional and end-user directed or focused. For example, web search engines, social media applications, marketing applications and retail applications may use and manipulate big data. Big data may be supported by a distributed database which allows the parallel processing capability of modern multi-process, multi-core servers to be fully utilized.